Addition agent for lubricating oils



Patented July 15, 1941 ADDITION AGENT FOR LUBRICATING OILS Eugene Lieber, Linden, N.

ard Oil Development Company,

of Delaware J., assignor to Standa corporation No Drawing. Application July 15, 1938,

Serial No. 219,354

15 Claims.

The present invention relates to improved addition agents for lubricating oils and more specifically to agents for reducing the pour point of waxy oils and for improving other properties as well.

It had been previously found that certain complex ketones had the power of increasing oiliness and in some instances reducing the pour point of waxy oils. The said ketones are of the general formula:

where R is a ring compound radical, either carbocyclic or heterocyclic, and R is an alky radical of at least 11 carbon atoms. These ketones are very weak pour inhibitors except in a few instances, particularly where complex polycyclic or condensed ring aromatic radicals are employed, such as anthracyl or phenanthryl radicals, and it would appear that compounds of this type would find whatever use they may have as oiliness agents.

It has now been found that better pour depressants can be made from naphthenic ketones which are of the following general formula:

where R. is an aromatic, hydroaromatic radical, or heterocyclic radical and R" is a naphthenic radical. These compounds differ very widely from the complex ketones heretofore described in that it appears that the preferable compounds of the present type contain monocyclicaromatic or heretocyclic radicals combined with the naphthenic group whereas the monocyclicalkyl ketones hitherto known have very little value as pour depressants. While there are other differences, these seem to suffice to show that the naphthenic-aromatlc or heterocyclic ketones do not follow the course that would be supposed from the known properties of the aromaticalkyl or heterocyclic-alkyl ketones.

The ketones referred to above, which constitute the present invention, are made by reaction of approximately equimolal quantities of naphthenic acidhalides, preferably naphthenic acid chloride, with aromatic hydroaromatic or heterocyclic compounds. The naphthenic acid chloride is obtained from naphthenic acids which occur naturally in certain crude oils, notably the so-called naphthenic crudes of the Texas Coastal region, from certain California crudes, as well as the crudes of Roumania, Aruba and Venezuela. The acids occur in almost all fractions from the kerosene range upward into the heavy lubricating oils. The acids are separated from the oil fractions by known methods and can be converted to the acid chloride by treatment with phosphorous tri or pentachlorides, or sulfuryl chloride or the like, at slightly elevated temperatures. As is well known, the acid halide may be also made from alkali metal salts of the acids as well as from the acids themselves. The products are then purified by distillation or otherwise.

As stated before, the naphthenic acid chloride or other halide is caused to react with a suitable aromatic, hydroaromatic, or heterocyclic compound in order to produce ketones. Among the suitable aromatics may be mentioned the hydrocarbons such as benzol, naphthalene, anthracene, diphenyl, xylene, or higher aromatics such as Propy1-, buty1-, amyl-benzenes, naphthalenes and the like. Hydrogenated aromatic hydrocarbons may also be employed such as cyclo-hexane, cyclo-hexene, tetra and decachlor naphthalene. Another group of compounds that are suitable are the oxygen-containing aromatics such as phenols and naphthol's. Cresols and the higher alkylated phenolic compounds are also useful, such as amylor butyl phenols and naphthols.

Aromatic ethers can be used for the present purpose such as diphenyl oxide, phenyl ether and complex aromatic-aliphatic ethers. Aromatic atives.

The reaction is brought about between thenaphthenic acid halide and the suitable aromatic or heterocyclic compound through the agency of the Friedel-Crafts type catalysts among which aluminum chloride, zinc chloride and the like may be mentioned. These are preferably employed in relatively large quantities, for example in substantially molecular proportions, preferably at room temperature or thereabout. The reaction is extremely vigorous and takes place quite rapidly although it is desirable to reflux the mixturefor an hour or more after the action. The product is then hydrolyzed, for example by adding water, aqueous alcohol or acid, and the ketone is then extracted with kerosene, naphtha or other suitable solvent from the inorganic products of hydrolysis. It may be recovered by distilling oi the acid.

The products obtained are of an oily character, in some cases heavy viscous oils, and in others are solid at room temperature. The color varies from a brilliant green to a dark brown. They are all soluble in mineral oils and some have excellent fluorescent properties, so that they may be used for this purpose in lubricating oil. Particularly desirable materials of this type are the hydroaromatic naphthenic ketones such as tetralin naphthenic ketone. Further, some of these products have the additional valuable property of imparting oiliness to natural mineral oils into which they are blended. For example, when added in even small amounts to mineral lubricating oils, say of the order 01 1 to 3%, there results a very marked improvement in the oiliness of the oil. The alkylated aniline naphthenic ketones are especially desirable for this specific use. When the compounds are to be usedas depressants for waxy oils, it is preferred that they be made from monocyclic aromatic materials, preferably the hydrocarbons or the hydroxy aromatics. The proportion in which they are added varies from about .1% to about 5%, but depends oi the particular product and on the oil to which it is-added. Some compounds are considerably more active than others and, as is well known, certain oils are much more susceptible to treatment than others. With reasonably small amounts, it i possible to obtain depressions of 20 to 50 F. .As an example of the method of making the present compounds, and their effectiveness in'oilpthe following data are ofi'ered. In each case the same procedure for manui'actm'ing the ketones 'was used and the products were tested in the 'same oil.

Example I 80 grams of naphthenic acids having an acid- A. S. T. M. ours of- R&R' p

- R=naphthenic radical R: 1% blend 5% blend Blank (Original Oil) +30 +30 Phenyl +30 +15 Phenanthryl +25 +10 0 Diphenyi.-. +20 0 Fiuoryl +25 +25 Oxy-phenyl- 0 20 Oxy-cresyl 0 -25 Diamyl-oxy-phenyl- +25 0 O-hydroxy-diphen +20 Amyl-beta-oxy-naphthyl. l5

15 AmyMXy-phenyI +10 l5 Anyl-phenyl-amyl-ether +20 5 Aniline +20 -15 Tetmii n +20 1O Xylen 5 AlphaFnaphthoL. +10 -15 Beta-naphtha] +15 20 Beta naphthylamine +20 15 2O PolY-amyl-naphthyl- +25 +10 Amyl-aniline 5 15 Phenyl other..." +20 0 Dimethyl aniline. +20

Diphenylamine +15 15 number of 212.5 and a saponification number of 214.8 were heated with 20 gram of phosphorus; trichloride on the water bath. The resultingnaphthenic acid chloride was decanted from the phosphorus acid and mixed with one molar proportion of the particular aromatic compound used contained in 100-150 cc. of tetrachlorethane as solvent. 40 grams of anhydrous AlCla were then slowly added to the reaction mixture while agitating at room temperature. Vigorous reaction took place with all of the aromatic compounds studied when adding the A1013 at room temperature. After the reaction of the AlCls, the reaction mixture was refluxed under areturn condenser for 3 hours. It was then poured into a mixture of alcohol and water and extracted, after cooling, with kerosene. The kerosene extract was then washedseveral times with the'water-alcohol mixture and then distilled with fire and steam had an original pour point of 30 F. and the pour depression was noted. The data are given in the table below:

Example I! The following example will illustrate the oiliness imparting properties of a number of the ketones whose preparation is described in Example I.

The test blends comprised 3% of the respective aromatic naphthenic ketone in a light lubricating oil. These were tested for oiliness imparting property by means of the "Almen lubricant testing machine." A description of the use of this machine for testing oiliness can be found in a monograph issued by the Virginia Polytechnic Institute by James I. Clower (see Bulletin #33, V. P. 1., vol. 27, No. 11, part 2, September, 1934).

The data obtained can be tabulated as follows:

Weights Ketone ed Unblended nn 2 Phenol naph 5 Oresoi hanhfhanin 7 C-amyl aniline flnnhfhnnin 12 where R is a naphthenic radical having a molecular weight at least as high as that of the naphthenic radicals obtainable from kerosene and R is a closed ring radical selected from the group consisting of poly-nuclear aromatic hydrocarbons and alkyl, hydrogenated, oxyand nitrogen derivatives of aromatic hydrocarbons.

2. Product according to claim 1 in which R is an aromatic radical.

3. Product according to claim 1 in which R is an oxy-aromatic radical.

4. Product comprising a lubricating oil and a minor amount of an alkylated aromatic amine naphthenic ketone.

5. Product comprising a lubricating oil and a v 11. A product according to claim 15 in which minor amount of amyl aniline naphthenic ketone.

6. An improved lubricating oil-blending agent comprising a mixed ketone condensation product from a Friedel-Crafts reaction of petroleum naphthenic acid chlorides with a cyclic organic compound, said ketone condensation. product beingconstituted by poly-nuclear naphthenic hydrocarbon radicals from the naphthenic acid chlorides joined to closed ring radicals of said cyclic organic compound through a ketone linkage.

7. A product according to claim 15 in which the closed ring radicalin an aromatic radical.

8. A product according to claim 15 in which said closed ring radical is an oxy-aromatic radical having a single oxygen group substituent in the aromatic ring.

9. A product according to claim 15 in which said closed ring radical is an aromatic amine radical.

10. A product according to claim 15 in which said closed ring radical is an alkylated aromatic amine radical.

said cyclic organic compound is amyl-aniline.

12. An improved lubricant comprising mineral lubricating oil and a ketone otthe following formula: R-fiI-R where R is a naphthenic radical and R is a heterocyclic radical.

' 13. Product according to claim 12 where R is an' oxygen-containing aromatic radicaL.

14. Product according-to claim 12 where R is a nitrogen-containing aromatic radical.

15. An improved product comprising a ketone of the following formula:

R-c-w 0 where R is a poly-nuclear naphthenic radical derived from a petroleum fraction at least as heavy as kerosene, and R'is a closed ring radical.

- EUGENE LIEBER. 

